The strange little black bird Nero, who kept following Asta around, suddenly appears before Finral, who had just finished fighting with his brother Langris, and demands that he take them to the Demon’s bones back in Hage Village. Finral is obviously startled that Nero’s suddenly speaking human words but obliges and takes Nero to the bones and witnesses an unbelievable sight. We will finally find out the true events that befell the elves 500 years ago! Meanwhile, back at the Shadow Palace, the devil’s eerie magic fills the room.

To stop the devil from leaving the Shadow Palace Asta, Yuno, and Patry, who had just regained his senses, head to the top floor. Once they get there, they are greeted by the first Wizard King, Lumiere Silvamillion Clover and the one who serves him, Secré Swallowtail。Secré is the true form of the mysterious bird, Nero, and she is a mage that uses a rare magic called sealing magic. She uses her magic to break the seal on Licht, and they are able to witness the true leader of the elves, Licht, and his true powers. An epic battle begins so that Licht and Lumiere can get revenge against the devil.